场景完成是从场景的部分扫描中完成缺失几何形状的任务。大多数以前的方法使用3D网格上的截断签名距离函数(T-SDF)计算出隐式表示,作为神经网络的输入。截断限制,但不会删除由非关闭表面符号引入的模棱两可的案例。作为替代方案,我们提出了一个未签名的距离函数(UDF),称为未签名的加权欧几里得距离(UWED)作为场景完成神经网络的输入表示。 UWED作为几何表示是简单而有效的,并且可以在任何点云上计算,而与通常的签名距离函数(SDF)相比,UWED不需要正常的计算。为了获得明确的几何形状,我们提出了一种从常规网格上离散的UDF值提取点云的方法。我们比较了从RGB-D和LIDAR传感器收集的室内和室外点云上的场景完成任务的不同SDF和UDFS,并使用建议的UWED功能显示了改进的完成。
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LIDAR传感器提供有关周围场景的丰富3D信息,并且对于自动驾驶汽车的任务(例如语义细分,对象检测和跟踪)变得越来越重要。模拟激光雷达传感器的能力将加速自动驾驶汽车的测试,验证和部署,同时降低成本并消除现实情况下的测试风险。为了解决以高保真度模拟激光雷达数据的问题,我们提出了一条管道,该管道利用移动映射系统获得的现实世界点云。基于点的几何表示,更具体地说,已经证明了它们能够在非常大点云中准确对基础表面进行建模的能力。我们引入了一种自适应夹层生成方法,该方法可以准确地对基础3D几何形状进行建模,尤其是对于薄结构。我们还通过在GPU上铸造Ray铸造的同时,在有效处理大点云的同时,我们还开发了更快的时间激光雷达模拟。我们在现实世界中测试了激光雷达的模拟,与基本的碎片和网格划分技术相比,表现出定性和定量结果,证明了我们的建模技术的优势。
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Paris-Carla-3d是由移动激光器和相机系统构建的几个浓彩色点云的数据集。数据由两组具有来自开源Carla模拟器(700百万分)的合成数据和在巴黎市中获取的真实数据(6000万分),因此Paris-Carla-3d的名称。此数据集的一个优点是在开源Carla模拟器中模拟了相同的LIDAR和相机平台,因为用于生产真实数据的开源Carla Simulator。此外,使用Carla的语义标记的手动注释在真实数据上执行,允许将转移方法从合成到实际数据进行测试。该数据集的目的是提供一个具有挑战性的数据集,以评估和改进户外环境3D映射的困难视觉任务的方法:语义分段,实例分段和场景完成。对于每项任务,我们描述了评估协议以及建立基线的实验。
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Reinforcement learning (RL) is a promising solution for autonomous vehicles to deal with complex and uncertain traffic environments. The RL training process is however expensive, unsafe, and time consuming. Algorithms are often developed first in simulation and then transferred to the real world, leading to a common sim2real challenge that performance decreases when the domain changes. In this paper, we propose a transfer learning process to minimize the gap by exploiting digital twin technology, relying on a systematic and simultaneous combination of virtual and real world data coming from vehicle dynamics and traffic scenarios. The model and testing environment are evolved from model, hardware to vehicle in the loop and proving ground testing stages, similar to standard development cycle in automotive industry. In particular, we also integrate other transfer learning techniques such as domain randomization and adaptation in each stage. The simulation and real data are gradually incorporated to accelerate and make the transfer learning process more robust. The proposed RL methodology is applied to develop a path following steering controller for an autonomous electric vehicle. After learning and deploying the real-time RL control policy on the vehicle, we obtained satisfactory and safe control performance already from the first deployment, demonstrating the advantages of the proposed digital twin based learning process.
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在全球范围内消除语言障碍的目标的驱动下,机器翻译已巩固自己是当今人工智能研究的关键重点。但是,这样的努力围绕着一小部分语言结合在一起,留下了绝大多数低资源的语言。在确保安全,高质量的结果的同时,在牢记道德考虑的同时,打破200个语言障碍需要什么?没有留下的语言,我们首先通过与母语人士的探索性访谈来解决对低资源语言翻译支持的必要性来应对这一挑战。然后,我们创建了旨在缩小低资源和高资源语言之间的性能差距的数据集和模型。更具体地说,我们开发了一种有条件的计算模型,基于专家的稀疏混合物,该模型经过针对针对低资源语言量身定制的新颖有效的数据挖掘技术培训的。我们提出了多次建筑和培训改进,以抵消数千个任务的培训。至关重要的是,我们使用人类翻译的基准,Flores-200评估了40,000多种不同的翻译方向的性能,并将人类评估与新型毒性基准相结合,涵盖Flores-200的所有语言,以评估翻译安全性。我们的模型相对于先前的最新技术,实现了44%BLEU的改善,为实现通用翻译系统奠定了重要的基础。最后,我们开源此工作中描述的所有贡献,可在https://github.com/facebookresearch/fairseq/tree/nllb上访问。
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我们介绍了一种普遍的策略,可实现有效的多目标勘探。它依赖于adagoal,一种基于简单约束优化问题的新的目标选择方案,其自适应地针对目标状态,这既不是太困难也不是根据代理目前的知识达到的。我们展示了Adagoal如何用于解决学习$ \ epsilon $ -optimal的目标条件的政策,以便在$ L $ S_0 $ S_0 $奖励中获得的每一个目标状态,以便在$ S_0 $中获取。免费马尔可夫决策过程。在标准的表格外壳中,我们的算法需要$ \ tilde {o}(l ^ 3 s a \ epsilon ^ { - 2})$探索步骤,这几乎很少最佳。我们还容易在线性混合Markov决策过程中实例化Adagoal,其产生具有线性函数近似的第一目标导向的PAC保证。除了强大的理论保证之外,迈克纳队以现有方法的高级别算法结构为锚定,为目标条件的深度加固学习。
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Recent advances in deep learning have enabled us to address the curse of dimensionality (COD) by solving problems in higher dimensions. A subset of such approaches of addressing the COD has led us to solving high-dimensional PDEs. This has resulted in opening doors to solving a variety of real-world problems ranging from mathematical finance to stochastic control for industrial applications. Although feasible, these deep learning methods are still constrained by training time and memory. Tackling these shortcomings, Tensor Neural Networks (TNN) demonstrate that they can provide significant parameter savings while attaining the same accuracy as compared to the classical Dense Neural Network (DNN). In addition, we also show how TNN can be trained faster than DNN for the same accuracy. Besides TNN, we also introduce Tensor Network Initializer (TNN Init), a weight initialization scheme that leads to faster convergence with smaller variance for an equivalent parameter count as compared to a DNN. We benchmark TNN and TNN Init by applying them to solve the parabolic PDE associated with the Heston model, which is widely used in financial pricing theory.
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Training a very deep neural network is a challenging task, as the deeper a neural network is, the more non-linear it is. We compare the performances of various preconditioned Langevin algorithms with their non-Langevin counterparts for the training of neural networks of increasing depth. For shallow neural networks, Langevin algorithms do not lead to any improvement, however the deeper the network is and the greater are the gains provided by Langevin algorithms. Adding noise to the gradient descent allows to escape from local traps, which are more frequent for very deep neural networks. Following this heuristic we introduce a new Langevin algorithm called Layer Langevin, which consists in adding Langevin noise only to the weights associated to the deepest layers. We then prove the benefits of Langevin and Layer Langevin algorithms for the training of popular deep residual architectures for image classification.
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Machine learning (ML) models can leak information about users, and differential privacy (DP) provides a rigorous way to bound that leakage under a given budget. This DP budget can be regarded as a new type of compute resource in workloads of multiple ML models training on user data. Once it is used, the DP budget is forever consumed. Therefore, it is crucial to allocate it most efficiently to train as many models as possible. This paper presents the scheduler for privacy that optimizes for efficiency. We formulate privacy scheduling as a new type of multidimensional knapsack problem, called privacy knapsack, which maximizes DP budget efficiency. We show that privacy knapsack is NP-hard, hence practical algorithms are necessarily approximate. We develop an approximation algorithm for privacy knapsack, DPK, and evaluate it on microbenchmarks and on a new, synthetic private-ML workload we developed from the Alibaba ML cluster trace. We show that DPK: (1) often approaches the efficiency-optimal schedule, (2) consistently schedules more tasks compared to a state-of-the-art privacy scheduling algorithm that focused on fairness (1.3-1.7x in Alibaba, 1.0-2.6x in microbenchmarks), but (3) sacrifices some level of fairness for efficiency. Therefore, using DPK, DP ML operators should be able to train more models on the same amount of user data while offering the same privacy guarantee to their users.
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Imperfect information games (IIG) are games in which each player only partially observes the current game state. We study how to learn $\epsilon$-optimal strategies in a zero-sum IIG through self-play with trajectory feedback. We give a problem-independent lower bound $\mathcal{O}(H(A_{\mathcal{X}}+B_{\mathcal{Y}})/\epsilon^2)$ on the required number of realizations to learn these strategies with high probability, where $H$ is the length of the game, $A_{\mathcal{X}}$ and $B_{\mathcal{Y}}$ are the total number of actions for the two players. We also propose two Follow the Regularize leader (FTRL) algorithms for this setting: Balanced-FTRL which matches this lower bound, but requires the knowledge of the information set structure beforehand to define the regularization; and Adaptive-FTRL which needs $\mathcal{O}(H^2(A_{\mathcal{X}}+B_{\mathcal{Y}})/\epsilon^2)$ plays without this requirement by progressively adapting the regularization to the observations.
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